Cluster Data Node Has Been Restarted

This new alert flags when a data node has been restarted (by default it alerts on any data node that has started in the last 10 minutes but you can change that interval if you wish). If you manually perform a restart (e.g. as part of a rolling upgrade) then you can safely ignore this alert (or you may even want to temporarily unschedule it first). However if the restart was spontaneous then this can be an early warning for you to take a look at the error logs and address any issues before the situation worsens.

Cluster DiskPageBuffer Hit Ratio Is Low (& associated graph)

The Disk Page Buffer is a cache on each data node which is used when using disk-based tables. Like any cache, the higher the hit rate the better the performance. Tuning the size of this cache can have a significant effect on your system – the new graph helps you see the results of your changes and the alert warns you when the ration falls below an acceptable level (this could happen for example temporarily after a data node restart or permanently when the active data set grows).

The ndbinfo database has a new table “diskpagebuffer” which contains the raw information needed to calculate the cache hit ration and it is the source of the data for the new alert and graph. If you wanted to calculate the cache hit ratio for yourself directly from this table then you can use the following query:

Join this session to learn about the latest enhancements to the MySQL Cluster database, enabling even more of the latest generation of web, telecoms and embedded applications to take advantage of high write scalability, SQL and NoSQL interfaces and 99.999% availability.

Integration with the MySQL 5.5 release, enabling users to fully exploit the latest capabilities of both the InnoDB and MySQL Cluster storage engines within a single application

Streamlined cluster provisioning and maintenance

The 2nd Development Milestone Release of MySQL Cluster 7.2.1 was announced at Oracle OpenWorld 2011. This release is now available for download and evaluation under the GPL license. This session will help to get you started with this latest release.

For those people that weren’t able to attend the MySQL Cluster demo or sessions at this year’s Oracle Open World (or even for those that did) and would like copies of the material, links are provided here.

NoSQL Access to MySQL: The Best of Both Worlds – Covers what people are looking for from NoSQL data stores and how MySQL Cluster can meet these needs (both in terms of database characteristics and the APIs offered to applications)

Getting the most out of MySQL on Windows – How to deliver Highly Available applications with MySQL on Windows (including replication, Windows Server Failover Clustering and MySQL Cluster) as well as the latest in MySQL tools and the Windows installer.